1. Field of the Invention
This invention relates to a color printing system wherein regions of rupturable capsules of a layer of capsules are ruptured to release dye that prints an color image on an image-receiving sheet, and more particularly the invention is directed to a color printing system which projects the plural monochrome pictures corresponding to the pictures separated into three primary colores onto the imaging sheet, and presses said sheets to transfer the dye from said imaging sheet to said image-receiving sheet.
2. Description of the Prior Art
For the purpose of hard-copying color pictures projected on a display screen of a CAD/CAM system, a thermotransferring printer or an inkjet printer is used. However, there are some problems, it takes long to print out, and only one color can be presented per dot so that the area of one picture element is large, therefore, pictures are roughly printed.
In order to solve the above problems, another approach, shown in U.S. Pat. No. 4,399,209 was proposed. The color imaging system has images formed by image-wise exposing a layer containing a dye and a photosensitive composition encapsulated in a layer of pressure rupturable microcapsules.
The above imaging system attains to present picture elements having the same sizes as those of the microcapsules. Therefore, color pictures can be printed with extremely high resolution.
However, since the imaging system requires surface scanning by use of three kinds of beams having mutually different energy ranges for printing a color picture, the optical system of scanning is complicated and it takes a long time to print one screen.